2.) Let \( \sim\) be the equivalence relation on \( {\mathbb{R}}_{\text{std}} \)
with one non-trivial class which is equal to \( \mathbb{Z} \). Show that
\( {\mathbb{R}}_{\text{std}}/\sim\) is not first countable. Thus, there is a closed,
continuous image of a second countable metric space which is not first countable.